[S] Change in coreboot[master]: soc/amd/common/block/cpu: Add missing cbfs_unmap()

[Jakub Czapiga (Code Review)]

Attention is currently required from: Konrad Adamczyk, Jason Glenesk, Raul Rangel, Matt DeVillier, Paul Menzel, Grzegorz Bernacki, Arthur Heymans, Tim Van Patten, Fred Reitberger, Karthik Ramasubramanian, Felix Held.

Jakub Czapiga has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/74777 )

Change subject: soc/amd/common/block/cpu: Add missing cbfs_unmap()
......................................................................

Patch Set 2:

(2 comments)

Commit Message:

https://review.coreboot.org/c/coreboot/+/74777/comment/305b83ff_fd1d01ff 
PS2, Line 12: BUG=278264488
Google bugs should use format: `BUG=b:9999` for buganizer or `BUG=chromium:9999` for public tracker.

File src/soc/amd/common/block/cpu/update_microcode.c:

https://review.coreboot.org/c/coreboot/+/74777/comment/a05885d2_3cbf7ad8 
PS2, Line 101: cbfs_unmap((void *)ucode);
             : 			ucode = NULL;
             : 			timestamp_add_now(TS_READ_UCODE_END);
             : 			return;
nit:
```
    timestamp_add_now(TS_READ_UCODE_END);
    goto end;

...

if (atomic_read(&cpus_updated) >= get_cpu_count()) {
end:
    	cbfs_unmap((void *)ucode);
    	ucode = NULL;
    }

```